Operating agricultural vehicle such as tractors and harvesters often requires highly repetitive operations. For example, when plowing or planting a field, an operator must make repeated passes across a field. Due to the repetitive nature of the work and irregularities in the terrain, gaps and overlaps in the rows of crops can occur. This can result in damaged crops, overplanting, or reduced yield per acre. As the size of agricultural vehicles and farming implements continues to increase, precisely controlling their motion becomes more important.
Guidance systems are increasingly used for controlling agricultural and environmental management equipment and operations such as road side spraying, road salting, and snow plowing where following a previously defined route is desirable. This allows more precise control of the vehicles than is typically realized than if the vehicle is steered by a human. Many rely upon furrow followers which mechanically detect whether the vehicle is moving parallel to a previously plowed plant furrow. However, these guidance systems are most effective in flat terrain and when detecting furrows plowed in a straight line. Additionally, many of these systems require factory installation and are too expensive or inconvenient to facilitate after market installation.